Automatic measurement of viscosity

ABSTRACT

The viscosity of a liquid is automatically measured by an apparatus comprising a Lantz-Zeitfuchs type reverse flow viscosimeter; a timing means actuated by photoelectric devices consisting of pairs of photoelectric cell and light source; a sequence control system; pumps and electromagnetic switch valves; said pumps and valves being internally communicated with said viscosimeter; said photoelectric cells being electrically connected to said sequence control system; whereby the actuations of said valves and pumps are programmed in sequence for measuring the time for viscosity counting, for washing and for drying the viscosimeter. The viscosimeter is placed in a constant temperature bath and has a timing bulb which is of one piece with protection tubes encasing light source lamps and photoelectric cells in pairs at the upper and lower timing marks of said bulb.

United States Patent 191 Aritomi [11] 3,713,328 1 Jan. 30, 1973 OTHERPUBLICATIONS Jones, G. et al., The Automatic Timing of the OstwaldViscometer by Means of a Photoelectric Cell, in Journal of Physics, Vol.4, pp. 215-224, June 1933.

Primary Examiner- Louis J. Capozi Assistant Examiner-Joseph W. RoskosAttorney-Fred C. Philpitt [57] ABSTRACT The viscosity of a liquid isautomatically measured by an apparatus comprising a Lantz-Zeitfuchs typereverse flow viscosimeter; a timing means actuated by photoelectricdevices consisting of pairs of photoelectric cell and light source; asequence control system; pumps and electromagnetic switch valves; saidpumps and valves being internally communicated with said viscosimeter;said photoelectric cells being electrically connected to said sequencecontrol system; whereby the actuations of said valves and pumps areprogrammed in sequence for measuring the time for viscosity counting,for washing and for drying the viscosimeter. The viscosimeter is placedin a constant temperature bath and has a timing bulb which is of onepiece with protection tubes encasing light source lamps andphotoelectric cells in pairs at the upper and lower timing marks of saidbulb.

8 Claims, 2 Drawing Figures SEQUENCE CONTROL MEANS I l I l TIMING MEANSPATENTEDJAI 30 I975 SHEET 1 [IF 2 FIG.

CONTROL MEANS SHEET 2 [IF 2 FIG.2

AUTOMATIC MEASUREMENT OF VISCOSITY This invention relates to a methodand an apparatus for automatically measuring the viscosity of a liquid,and more particularly to an apparatus for automatically measuring theviscosity based on Lantz-Zeitfuchs Hantz-Zeitfuchs type reverse flowviscosimeter.

As for apparatuses for automatically measuring viscosity, there havebeen heretofore known those supplied from Precision Scientific Co.,U.S.A., which are based upon an Atlantic viscosimeter and those suppliedfrom Rigo-sha company, Japan, which are based upon 1 an Atlanticviscosimeter, a Cannon-Fenske routine viscosimeter, a Cannon-Fenskeopaque viscosimeter and a Ubbelohde viscosimeter. Since the fonnerapparatus is based on an Atlantic viscosimeter, its samples arerestricted only to transparent liquids and no leakage is permitted fromthe valve for holding the sample in a measuring bulb. Furthermore, theviscosimeter is so shaped that its suction-exhaust pipe must penetratethrough the bottom of a constant-temperature bath to be open beneath thebottom, so it is very bothersome to replace a defective one with a goodone. I

In the latter apparatus, a viscosimeter selected from an Atlanticviscosimeter, a Cannon-Fenske routine viscosimeter, a Cannon-Fenskeopaque viscosimeter and an Ubbelohde viscosimeter can be employed. Theyall have the same disadvantages as do the former. In the latterapparatuses based on viscosimeters other than the Atlantic type one, theviscosimeters must be turned upside down in sampling or in washing.

It is an object of the present invention to provide a method and anapparatus for automatically measuring the viscosity of opaque liquids aswell as transparent ones accurately without being attended by theabovementioned drawbacks of the conventional methods.

In the method for automatically measuring viscosity, the above-mentioneddrawbacks of conventional methods have been overcome by using theLantz-Zeitfuchs type viscosimeter; a timing means actuated byphotoelectric devices consisting of pairs of photoelectric cell andcorresponding light source which sense the top surface of a liquidsample passing across the upper and lower timing marks of a timemeasuring bulb to effect time measurement; electromagnetic valves formeasuring the time for viscosity counting, for washing and drying of theviscosimeter and a sequence control means for programming the actuationsof said valves as well as pumps to be described hereinafter. That is,

these photoelectric devices sense change in the intensity of light onthe passage of the sample across the two timing marks, whereby the timespent in the passage of the top surface of the sample between the upperand lower timing marks is measured. The pairs of light source lamps andthe corresponding photoelectric cells employed on the timing bulb havebeen conventionally used with or without encasement in water-proofcases, but in both cases air or steam bubbles are liable to form andstay in narrow clearances between the viscosimeter body and the nakedphotoelectric devices or the cases thereof and the bubbles often makethe photoelectric devices deviate from the normal readings.

The Lantz-Zeitfuchs viscosimeter referred to above is described on page941 of the 1968 Book of ASTM Standards, Part 17, relating tospecifications for kinematic glass viscometers.

As a result of various studies on the disadvantages so far encounteredin the conventional apparatuses for automatically measuring theviscosity, the present inventor has found that these disadvantages canbe completely overcome, by incorporating a Lantz-Zeitfu chs type reverseflow viscosimeter into the apparatus in the first embodiment of thepresent invention. Protection tubes for the photoelectric devicesconsisting of pairs of light source lamps and photoelectric cells areformed with the viscosimeter body to form a one piece assembly at theupper and lower timing marks of a timing bulb in the second embodimentof the present invention.

In the second embodiment of the present invention, since the protectiontubes for the photoelectric devices are connected to, and form one piecewith the viscosimeter body, there is no room for the formation of air'orsteam bubbles within the light path of the photoelectric devices and asa result, no error is introduced into the measurement by thephotoelectric devices.

Now, the present invention will be explained in more detail, referringto the accompanying drawings:

FIG. 1 is a schematic diagram of an apparatus for automaticallymeasuring the viscosity of a liquid according to the first embodiment ofthe present invention, where an area encircled by a dotted line denotesa constant temperature bath.

FIG. 2 is a detailed view of the photoelectric devices encased in theprotection tubes integrally connected to the viscosimeter body accordingto the second embodiment of the present invention.

As illustrated in FIG. 1, to measure the viscosity of a liquid, aconstant-temperature bath 18 is turned on and adjusted, first of all, tohave a prescribed constant temperature. Then, an electromagnetic valve11 is opened by manually starting the timer in the sequence controlmeans 20 (hereafter the actuations of the electromagnetic valves andpumps are automatically carried out in accordance with the programming).The adjustment of the constant-temperature bath and the actuation of thesequence control means are effected automatically and independentlyafter once started manually. A fill bulb 2 is manually filled with asample from an inlet 1 of the viscosimeter to such an extent that asmall amount is overflown. The sample in the fill bulb '2 is left tostand for a predetermined time to attain a constant temperature the sameas that of bath 18. The electromagnetic vent valve 11 is closed, anelectromagnetic suction valve 10 is opened and a suction pump 12 isstarted, whereby a siphon of the sample is formed at the inverted U-typetube part 4 of the viscosimeter. Then, immediately the electromagneticsuction valve 10 is closed and the electromagnetic vent valve 11 isopened simultaneously. Thereafter, the sample starts flowing by gravitythrough a capillary tube 5 by the principle of a siphonal action and thetop surface of it comes up the other column having a timing bulb 7through the lower part of the timing bulb and reaches the upper partthereof. Photoelectric devices 6 and 8, provided respectively at thelower and the upper marks 22, 23 (shown in FIG. 2) of the timing bulk 21(indicated as 7 in FIG. I), sense the passage of the top surface of thesample across said marks and signal a timing means 19 to measure thetime spent by the passage of the top surface of the same between thetiming marks 22 and 23 automatically.

After the measurement of the time for viscosity counting is completed inthe foregoing procedure, washing of the inside of the viscosimeterfollows.

In washing, the electromagnetic vent valve 11 is closed, theelectromagnetic suction valve is opened, and the used sample isdischarged by a suction pump 12. Then, the electromagnetic suction valve10 is closed, an electromagnetic discharge valve 9 is opened, and thesurplus sample in an overflow bulb 3 is discharged by a suction pump 12.Then, the electromagnetic suction valve 10 is opened, an electromagneticcontrol valve is opened while actuating the suction pump 12, and awashing liquid is introduced into the viscosimeter from a washing liquidreservoir 13 by the actuation of a supply pump 17 for supplying awashing liquid to rinse the inside of the viscosimeter. The pump 17, isalso used for supplying a drying liquid as hereinafter described. Therinsing is continued for a predetermined time. Then, the electromagneticcontrol valve 15 is closed, an electromagnetic control valve 16 for aviscosimeter-drying liquid is opened, and the drying liquid isintroduced into the viscosimeter from a drying liquid vessel 14. Theelectromagnetic control valve 16 is closed after a predetermined timeand the supply pump 17 is then stopped. The suction pump 12 stillcontinues to work thereafter to allow air to flow through theviscosimeter for drying. After the drying is completed, theelectromagneticdischarge valve 9 is closed, the electromagnetic suctionvalve 10 is closed and the suction pump 12 is stopped. After thecompletion of the drying all the electrical components are deenergized,except the bath 18, by the actuation of the sequence control means 20.Further, before the readout counter of the timing means 19 is clearedoff to zero manually for the next measurement, the readoffout must beread.

Toluene, or similar hydrocarbons, are preferable as the'washing liquorfor the viscosimeter. Acetone, or similar organic liquids, arepreferable as the drying liquor for the viscosimeter.

As illustrated in FIG. 2, protection tubes 24-27, consisting of glass,etc., are formed as integral parts of the viscosity body, but are notopen to nor communicate with the liquid passageway in the viscositybody. These tubes encase light source lamps 28 and 29 and photoelectriccells 30 and 31 corresponding thereto, at the upper and lower timingmarks 22 and 23 ofa timing bulb 21 of the viscosimeter. Lead-out wires32 of the photoelectric means are extended out of theconstanttemperature bath, without being wetted, through tubings 33consisting of plastics, rubber, etc. which are connected to the openends of the protection tubes 24-27.

What is claimed is:

1. An apparatus for automatically measuring the viscosity of a liquidwhich comprises,

a. a Lantz-Zeitfuchs reverse flow viscosimeter, said viscosimeterdefining a timing bulb, a fill bulb, and

a discharge outlet,

b. photosensing means mounted adjacent said timing bulb to sense thepassage of a liquid through said bulb, a

c. timing means connected to said photoelectric means to measure thetime required by the liquid to pass through said timing bulb,

d. means for automatically evacuating the liquid from the viscosimeterthrough said discharge outlet,

e. sequence control means for automatically starting the flow of liquidin said viscosimeter, energizing said timing means, and evacuating saidliquid after said timing means has completed its measurement.

2. An apparatus for automatically measuring the viscosity of a liquid asclaimed in claim 1 which further comprises means for automaticallywashing and drying said viscosimeter, said means being controlled bysaid sequence control means.

3. An apparatus for automatically measuring the viscosity of a liquid asclaimed in claim 2 wherein said means for washing and drying saidviscosimeter further comprise reservoirs for washing and drying agents,control valves for selectively discharging said agents into said fillbulb, and pump means for assisting in the discharge of said agents, saidsequence control means selectively actuating said valves and said pump.

4. An apparatus for automatically measuring the viscosity of a liquid asclaimed in claim 1 wherein said timing bulb further defines protectivetubes for encasing a light source means and photosensing means at theupper and lower portions of said timing bulb.

5. An apparatus for automatically measuring the viscosity of a liquid asclaimed in claim 1 wherein said Lantz-Zeitfuchs reverse flowviscosimeter further defines an inlet portion, said inlet portion beingconnected to said fill bulb, an overflow bulb connected to theinterconnection between said inlet portion and said fill bulb through adownwardly inclined tube, an inverted U-type tube section connected tothe bottom of said fill bulb, a U-type capillary tube connected to theoutlet end of said inverted U-type tube, said timing bulb connected tothe outlet end of said U-type capillary tube, and said discharge outletconnected to the upper end of said timing bulb.

6. An apparatus for automatically measuring the viscosity of a liquid asclaimed in claim 1 wherein said means for automatically evacuating theliquid comprise a discharge valve, a suction valve, a vent valve, andpump means for generating a vacuum. I

7. An apparatus for automatically measuring the viscosity of a liquidwhich comprises a. a viscosimeter, said viscosimeter defining a fillbulb, a capillary portion, a timing bulb, and a discharge outlet,

. photosensing means mounted adjacent said timing bulb to sense thepassage of a liquid through said bulb,

c. timing means connected to said photosensing means to measure the timerequired by the liquid to pass through said timing bulb,

. means for automatically evacuating the liquid from the viscosimeterthrough said discharge outlet opening, said means comprising a dischargevalve, a vent valve, a suction valve, and pump means for generating avacuum,

e. means for washing and drying said viscosimeter, said means comprisingreservoirs for washing and drying agents, control valves for selectivelydischarging said agents into said fill bulb, and pump means forassisting in the discharge of said agents to said fill bulb, and

f. sequence control means for automatically starting the flow of liquidin said viscosimeter, energizing said timing means, evacuating saidliquid after said timing means has completed its measurement, andwashing and drying said viscosimeter after said liquid has beenevacuated.

1. An apparatus for automatically measuring the viscosity of a liquidwhich comprises, a. a Lantz-Zeitfuchs reverse flow viscosimeter, saidviscosimeter defining a timing bulb, a fill bulb, and a dischargeoutlet, b. photosensing means mounted adjacent said timing bulb to sensethe passage of a liquid through said bulb, c. timing means connected tosaid photoelectric means to measure the time required by the liquid topass through said timing bulb, d. means for automatically evacuating theliquid from the viscosimeter through said discharge outlet, e. sequencecontrol means for automatically starting the flow of liquid in Saidviscosimeter, energizing said timing means, and evacuating said liquidafter said timing means has completed its measurement.
 1. An apparatusfor automatically measuring the viscosity of a liquid which comprises,a. a Lantz-Zeitfuchs reverse flow viscosimeter, said viscosimeterdefining a timing bulb, a fill bulb, and a discharge outlet, b.photosensing means mounted adjacent said timing bulb to sense thepassage of a liquid through said bulb, c. timing means connected to saidphotoelectric means to measure the time required by the liquid to passthrough said timing bulb, d. means for automatically evacuating theliquid from the viscosimeter through said discharge outlet, e. sequencecontrol means for automatically starting the flow of liquid in Saidviscosimeter, energizing said timing means, and evacuating said liquidafter said timing means has completed its measurement.
 2. An apparatusfor automatically measuring the viscosity of a liquid as claimed inclaim 1 which further comprises means for automatically washing anddrying said viscosimeter, said means being controlled by said sequencecontrol means.
 3. An apparatus for automatically measuring the viscosityof a liquid as claimed in claim 2 wherein said means for washing anddrying said viscosimeter further comprise reservoirs for washing anddrying agents, control valves for selectively discharging said agentsinto said fill bulb, and pump means for assisting in the discharge ofsaid agents, said sequence control means selectively actuating saidvalves and said pump.
 4. An apparatus for automatically measuring theviscosity of a liquid as claimed in claim 1 wherein said timing bulbfurther defines protective tubes for encasing a light source means andphotosensing means at the upper and lower portions of said timing bulb.5. An apparatus for automatically measuring the viscosity of a liquid asclaimed in claim 1 wherein said Lantz-Zeitfuchs reverse flowviscosimeter further defines an inlet portion, said inlet portion beingconnected to said fill bulb, an overflow bulb connected to theinterconnection between said inlet portion and said fill bulb through adownwardly inclined tube, an inverted U-type tube section connected tothe bottom of said fill bulb, a U-type capillary tube connected to theoutlet end of said inverted U-type tube, said timing bulb connected tothe outlet end of said U-type capillary tube, and said discharge outletconnected to the upper end of said timing bulb.
 6. An apparatus forautomatically measuring the viscosity of a liquid as claimed in claim 1wherein said means for automatically evacuating the liquid comprise adischarge valve, a suction valve, a vent valve, and pump means forgenerating a vacuum.
 7. An apparatus for automatically measuring theviscosity of a liquid which comprises a. a viscosimeter, saidviscosimeter defining a fill bulb, a capillary portion, a timing bulb,and a discharge outlet, b. photosensing means mounted adjacent saidtiming bulb to sense the passage of a liquid through said bulb, c.timing means connected to said photosensing means to measure the timerequired by the liquid to pass through said timing bulb, d. means forautomatically evacuating the liquid from the viscosimeter through saiddischarge outlet opening, said means comprising a discharge valve, avent valve, a suction valve, and pump means for generating a vacuum, e.means for washing and drying said viscosimeter, said means comprisingreservoirs for washing and drying agents, control valves for selectivelydischarging said agents into said fill bulb, and pump means forassisting in the discharge of said agents to said fill bulb, and f.sequence control means for automatically starting the flow of liquid insaid viscosimeter, energizing said timing means, evacuating said liquidafter said timing means has completed its measurement, and washing anddrying said viscosimeter after said liquid has been evacuated.